scholarly journals Ultrasound Microbubble–Facilitated Inner Ear Delivery of Gold Nanoparticles Involves Transient Disruption of the Tight Junction Barrier in the Round Window Membrane

2021 ◽  
Vol 12 ◽  
Author(s):  
Yi-Chun Lin ◽  
Cheng-Ping Shih ◽  
Hsin-Chien Chen ◽  
Ying-Liang Chou ◽  
Huey-Kang Sytwu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Tight Junction ◽  
Inner Ear ◽  
Laser Scanning ◽  
Round Window ◽  
Combined Treatment ◽  
Laser Scanning Microscopy ◽  
Ultrastructural Changes ◽  
Confocal Laser ◽  
Round Window Membrane

The application of ultrasound microbubbles (USMBs) enhances the permeability of the round window membrane (RWM) and improves drug delivery to the inner ear. In this study, we investigated the efficiency of USMB-aided delivery of chitosan-coated gold nanoparticles (CS-AuNPs) and the mechanism of USMB-mediated enhancement of RMW permeability. We exposed mouse inner ears to USMBs at an intensity of 2 W/cm2 and then filled the tympanic bulla with CS-AuNPs or fluorescein isothiocyanate-decorated CS-AuNPs (FITC-CS-AuNPs). The membrane uptake of FITC-CS-AuNPs and their depth of permeation into the three-layer structure of the RWM, with or without prior USMB treatment, were visualized by z-stack confocal laser scanning microscopy. Ultrastructural changes in the RWM due to USMB-mediated cavitation appeared as sunburn-like peeling and various degrees of depression in the RWM surface, with pore-like openings forming in the outer epithelium. This disruption of the outer epithelium was paralleled by a transient reduction in tight junction (TJ)-associated protein levels in the RWM and an enhanced delivery of FITC-CS-AuNPs into the RWM. Without prior USMB exposure, the treatment with CS-AuNPs also caused a noticeable reduction in TJ proteins of the RWM. Our findings indicated that the combined treatment with USMBs and CS-AuNPs represents a promising and efficient drug and gene delivery vehicle for a trans-RWM approach for inner ear therapy. The outer epithelial layer of the RWM plays a decisive role in controlling the transmembrane transport of substances such as CS-AuNPs following the administration of USMBs. Most importantly, the enhanced permeation of AuNPs involved the transient disruption of the TJ-created paracellular barrier in the outer epithelium of the RWM.

scholarly journals In Situ 3D-Imaging of the Inner Ear Synapses with a Cochlear Implant

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 301
Author(s):  
Kathrin Malfeld ◽  
Nina Armbrecht ◽  
Holger A. Volk ◽  
Thomas Lenarz ◽  
Verena Scheper
Keyword(s):  
Cochlear Implant ◽  
Inner Ear ◽  
Laser Scanning ◽  
3D Imaging ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Sensory Cells ◽  
Residual Hearing ◽  
Preparation Methods

In recent years sensorineural hearing loss was found to affect not exclusively, nor at first, the sensory cells of the inner ear. The sensory cells’ synapses and subsequent neurites are initially damaged. Auditory synaptopathies also play an important role in cochlear implant (CI) care, as they can lead to a loss of physiological hearing in patients with residual hearing. These auditory synaptopathies and in general the cascades of hearing pathologies have been in the focus of research in recent years with the aim to develop more targeted and individually tailored therapeutics. In the current study, a method to examine implanted inner ears of guinea pigs was developed to examine the synapse level. For this purpose, the cochlea is made transparent and scanned with the implant in situ using confocal laser scanning microscopy. Three different preparation methods were compared to enable both an overview image of the cochlea for assessing the CI position and images of the synapses on the same specimen. The best results were achieved by dissection of the bony capsule of the cochlea.

scholarly journals Silver Nanoparticles Formation by Jatropha integerrima and LC/MS-QTOF-Based Metabolite Profiling

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2400
Author(s):  
Afrah E. Mohammed ◽  
Lamya Ahmed Al-Keridis ◽  
Ishrat Rahman ◽  
Modhi O. Alotaibi ◽  
Rasha Saad Suliman ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Laser Scanning ◽  
Antibacterial Effect ◽  
Therapeutic Potential ◽  
Laser Scanning Microscopy ◽  
Ultrastructural Changes ◽  
Confocal Laser ◽  
Synthesis Methods ◽  
Tem Analysis ◽  
Average Size

The broad application of metal nanoparticles in different fields encourages scientists to find alternatives to conventional synthesis methods to reduce negative environmental impacts. Herein, we described a safe method for preparing silver nanoparticles (J-AgNPs) using Jatropha integerrima leaves extract as a reducing agent and further characterize its physiochemical and pharmacological properties to identify its therapeutic potential as a cytotoxic and antimicrobial agent. The biogenic synthesized J-AgNPs were physiochemically characterized by ultraviolet-visible spectroscopy, dynamic light scattering (DLS), transmission electron microscope (TEM), and energy-dispersive X-ray spectroscopy. HPLC-DAD, followed by LC/MS and the Fourier-transform infrared spectroscopy (FTIR), was applied to detect the biomolecules of J. integerrima involved in the fabrication of NPs. Furthermore, J-AgNPs and the ampicillin-nanocomposite conjugate were investigated for their potential antibacterial effects against four clinical isolates. Finally, cytotoxic effects were also investigated against cancer and normal cell lines, and their mechanism was assessed using TEM analysis and confocal laser scanning microscopy (LSM). Ag ions were reduced to spherical J-AgNPs, with a zeta potential of −34.7 mV as well as an average size of 91.2 and 22.8 nm as detected by DLS and TEM, respectively. HPLC GC/MC analysis identified five biomolecules, and FTIR suggested the presence of proteins besides polyphenolic molecules; together, these molecules could be responsible for the reduction and capping processes during NP formation. Additionally, J-AgNPs displayed a strong antibacterial effect, although the ampicillin conjugated form had a very weak antibacterial effect. Furthermore, the NPs caused a reduction in cell viability of all the treated cells by initiating ultrastructural changes and apoptosis, as identified by TEM and LSM analysis. Therefore, J-AgNPs can be formed using the leaf extract from the J. integerrima plant. Furthermore, J-AgNPs may serve as a candidate for further biochemical and pharmacological testing to identify its therapeutic value.

A 3-Dimensional Model of the Human Round Window Membrane

2019 ◽  
Vol 128 (6_suppl) ◽  
pp. 103S-110S
Author(s):  
Yasuya Nomura ◽  
Toru Tanaka ◽  
Hitome Kobayashi ◽  
Yurika Kimura ◽  
Yurie Soejima ◽  
...  
Keyword(s):  
Cross Sections ◽  
Laser Scanning ◽  
Round Window ◽  
Gross Anatomy ◽  
Laser Scanning Microscopy ◽  
Round Window Membrane ◽  
Dimensional Model ◽  
Anterior Portion ◽  
Posterior Portion ◽  
3 Dimensional

Objectives: The round window membrane (RWM) is small in size, making it difficult to clarify its shape and structure. The authors examined a 40x magnified 3-dimensional model of the human RWM to clarify its morphologic aspects and characteristics. Methods: An RWM specimen was obtained from an archival, formalin-fixed, decalcified, left temporal bone of an 84-year-old female cadaver. The data obtained by laser scanning microscopy were input into a 3-dimensional printer. After a model of the RWM was created, the following features were examined: striae on the surfaces, curvatures, thickness, and areas. Cross sections of the original specimen were made for histological observations. Results: The contour of this RWM model was approximately elliptic, with a saddle shape. When illuminated from the scala tympani side, the surface facing the fossula exhibited dark anterior and clear posterior portions. A borderline appeared where the 2 portions were bound along the short axis of the ellipse. This borderline was identified as the line of inflection. Collagen fibers were shown to run parallel to the borderline in the posterior portion but were fanned out in the anterior portion. Conclusions: The magnified 3-dimensional model clarified gross anatomy and characteristics of the RWM. It is good teaching material for small tissues, such as the RWM.

scholarly journals Quantitative Assessment of Root Canal Roughness with Calcium-Based Hypochlorite Irrigants by 3D CLSM

2014 ◽  
Vol 25 (5) ◽  
pp. 409-415 ◽  
Author(s):  
Juliana Santos Oliveira ◽  
Walter Raucci Neto ◽  
Natália Spadine de Faria ◽  
Fernanda Silva Fernandes ◽  
Carlos Eduardo Saraiva Miranda ◽  
...  
Keyword(s):  
Root Canal ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Ultrastructural Changes ◽  
Confocal Laser ◽  
Saline Control ◽  
Calcium Hypochlorite ◽  
Canal Irrigation ◽  
Root Canal Irrigation ◽  
Root Canal Dentin

Chemical solutions play important roles in endodontic treatment and promote ultrastructural changes in dentin surface. The aim of this study was to quantify root canal roughness at different concentrations of calcium hypochlorite (Ca(OCl)2) and sodium hypochlorite (NaOCl) by confocal laser scanning microscopy (CLSM). Fifty-two human mandibular premolars were sectioned and randomly organized into thirteen groups (n=8): saline (control); 1%, 2.5% and 5% NaOCl; 1%, 2.5% and 5% Ca(OCl)2; the hypochlorite groups were further divided into with or without EDTA. The chlorine concentrations of the different solutions were measured by iodine titration (%). The superficial roughness (Sa) was quantified by CLSM. Ca(OCl)2 presented substantial decrease in chlorine concentration that differed from the package indication, but without compromising the dentin ultrastructure changes. There were no significant differences in dentin roughness between Ca(OCl)2 or NaOCl at all studied concentrations. The combination with EDTA provided similar roughness values among the solutions (p>0.05). The 5% Ca(OCl)2 and NaOCl solutions significantly increased dentin roughness and did not differ from the EDTA association (p>0.05). Ca(OCl)2 promoted similar dentin roughness as the NaOCl at the same concentrations and combined with EDTA. It may be concluded that Ca(OCl)2 modified the root canal dentin roughness similarly to NaOCl, at the same concentrations and EDTA combinations used in this study. Ca(OCl)2 and NaOCl, both at 5%, significantly altered dentin roughness, overcoming EDTA association, thus Ca(OCl)2 concentrations ranging from 1% to 2.5% may be suitable solutions for root canal irrigation protocols.

Application of gold nanoparticles as contrast agents in confocal laser scanning microscopy

2009 ◽  
Vol 6 (1) ◽  
pp. 71-75 ◽  
Author(s):  
A. Lemelle ◽  
B. Veksler ◽  
I.S. Kozhevnikov ◽  
G.G. Akchurin ◽  
S.A. Piletsky ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Contrast Agents ◽  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser

scholarly journals Observation of Surface Structure and Nerve Innervation in Inner Ear End Organs by Confocal Laser Scanning Microscopy.

1997 ◽  
Vol 30 (4) ◽  
pp. 341-343 ◽  
Author(s):  
Hiroshi Yamashita ◽  
Toshikazu Gondo ◽  
Tokuhiro Ishihara ◽  
Hiroaki Shimogori ◽  
Masahiro Takahashi
Keyword(s):  
Surface Structure ◽  
Inner Ear ◽  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser

scholarly journals Synergistic Removal of Static and Dynamic Staphylococcus aureus Biofilms by Combined Treatment with a Bacteriophage Endolysin and a Polysaccharide Depolymerase

Viruses ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 438 ◽  
Author(s):  
Nanna Olsen ◽  
Elowine Thiran ◽  
Tobias Hasler ◽  
Thomas Vanzieleghem ◽  
Georgios Belibasakis ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Laser Scanning ◽  
Combined Treatment ◽  
Viable Cell ◽  
Laser Scanning Microscopy ◽  
Enzyme Treatment ◽  
Confocal Laser ◽  
Cell Counts ◽  
Glass Surfaces ◽  
Individual Enzyme

Staphylococcus aureus is an important pathogen and biofilm former. Biofilms cause problems in clinics and food production and are highly recalcitrant to antibiotics and sanitizers. Bacteriophage endolysins kill bacteria by degrading their cell wall and are therefore deemed promising antimicrobials and anti-biofilm agents. Depolymerases targeting polysaccharides in the extracellular matrix have been suggested as parts of a multi-enzyme approach to eradicate biofilms. The efficacy of endolysins and depolymerases against S. aureus biofilms in static models has been demonstrated. However, there is a lack of studies evaluating their activity against biofilms grown under more realistic conditions. Here, we investigated the efficacy of the endolysin LysK and the poly-N-acetylglucosamine depolymerase DA7 against staphylococcal biofilms in static and dynamic (flow cell-based) models. LysK showed activity against multiple S. aureus strains, and both LysK and DA7 removed static and dynamic biofilms from polystyrene and glass surfaces at low micromolar and nanomolar concentrations, respectively. When combined, the enzymes acted synergistically, as demonstrated by crystal violet staining of static biofilms, significantly reducing viable cell counts compared to individual enzyme treatment in the dynamic model, and confocal laser scanning microscopy. Overall, our results suggest that LysK and DA7 are potent anti-biofilm agents, alone and in combination.

scholarly journals Synthesis of Gold Nanoparticles Using Mimosa tenuiflora Extract, Assessments of Cytotoxicity, Cellular Uptake, and Catalysis

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Ericka Rodríguez-León ◽  
Blanca E. Rodríguez-Vázquez ◽  
Aarón Martínez-Higuera ◽  
César Rodríguez-Beas ◽  
Eduardo Larios-Rodríguez ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Laser Scanning ◽  
Nuclear Periphery ◽  
Laser Scanning Microscopy ◽  
Tree Bark ◽  
Bark Extract ◽  
Confocal Laser ◽  
Dependent Manner ◽  
X Ray ◽  
Mimosa Tenuiflora

Abstract Synthesis of gold nanoparticles (AuNPs) with plant extracts has gained great interest in the field of biomedicine due to its wide variety of health applications. In the present work, AuNPs were synthesized with Mimosa tenuiflora (Mt) bark extract at different metallic precursor concentrations. Mt extract was obtained by mixing the tree bark in ethanol-water. The antioxidant capacity of extract was evaluated using 2,2-diphenyl-1-picrylhydrazyl and total polyphenol assay. AuNPs were characterized by transmission electron microscopy, X-ray diffraction, UV-Vis and Fourier transform infrared spectroscopy, and X-ray photoelectron spectrometry for functional group determination onto their surface. AuMt (colloids formed by AuNPs and molecules of Mt) exhibit multiple shapes with sizes between 20 and 200 nm. AuMt were tested on methylene blue degradation in homogeneous catalysis adding sodium borohydride. The smallest NPs (AuMt1) have a degradation coefficient of 0.008/s and reach 50% degradation in 190s. Cell viability and cytotoxicity were evaluated in human umbilical vein endothelial cells (HUVEC), and a moderate cytotoxic effect at 24 and 48 h was found. However, toxicity does not behave in a dose-dependent manner. Cellular internalization of AuMt on HUVEC cells was analyzed by confocal laser scanning microscopy. For AuMt1, it can be observed that the material is dispersed into the cytoplasm, while in AuMt2, the material is concentrated in the nuclear periphery.

scholarly journals Transport of ultrasmall gold nanoparticles (2 nm) across the blood–brain barrier in a six-cell brain spheroid model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Viktoriya Sokolova ◽  
Gehad Mekky ◽  
Selina Beatrice van der Meer ◽  
Michael C. Seeds ◽  
Anthony J. Atala ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Blood Brain Barrier ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Brain Barrier ◽  
Confocal Laser ◽  
Hydrodynamic Diameter ◽  
Core Diameter ◽  
Blood Brain

Abstract The blood–brain barrier (BBB) is an efficient barrier for molecules and drugs. Multicellular 3D spheroids display reproducible BBB features and functions. The spheroids used here were composed of six brain cell types: Astrocytes, pericytes, endothelial cells, microglia cells, oligodendrocytes, and neurons. They form an in vitro BBB that regulates the transport of compounds into the spheroid. The penetration of fluorescent ultrasmall gold nanoparticles (core diameter 2 nm; hydrodynamic diameter 3–4 nm) across the BBB was studied as a function of time by confocal laser scanning microscopy, with the dissolved fluorescent dye (FAM-alkyne) as a control. The nanoparticles readily entered the interior of the spheroid, whereas the dissolved dye alone did not penetrate the BBB. We present a model that is based on a time-dependent opening of the BBB for nanoparticles, followed by a rapid diffusion into the center of the spheroid. After the spheroids underwent hypoxia (0.1% O2; 24 h), the BBB was more permeable, permitting the uptake of more nanoparticles and also of dissolved dye molecules. Together with our previous observations that such nanoparticles can easily enter cells and even the cell nucleus, these data provide evidence that ultrasmall nanoparticle can cross the blood brain barrier.

scholarly journals Ultrasmall gold and silver/gold nanoparticles (2 nm) as autofluorescent labels for poly(D,L-lactide-co-glycolide) nanoparticles (140 nm)

2020 ◽  
Vol 31 (12) ◽  
Author(s):  
Karolin Wey ◽  
Matthias Epple
Keyword(s):  
Gold Nanoparticles ◽  
Fluorescence Spectroscopy ◽  
Metallic Nanoparticles ◽  
Laser Scanning ◽  
Stokes Shift ◽  
Fluorescein Isothiocyanate ◽  
Plga Nanoparticles ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Water Emulsion

AbstractUltrasmall metallic nanoparticles show an efficient autofluorescence after excitation in the UV region, combined with a low degree of fluorescent bleaching. Thus, they can be used as fluorescent labels for polymer nanoparticles which are frequently used for drug delivery. A versatile water-in-oil-in-water emulsion-evaporation method was developed to load poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles with autofluorescent ultrasmall gold and silver/gold nanoparticles (diameter 2 nm). The metallic nanoparticles were prepared by reduction of tetrachloroauric acid with sodium borohydride and colloidally stabilised with 11-mercaptoundecanoic acid. They were characterised by UV–Vis and fluorescence spectroscopy, showing a large Stokes shift of about 370 nm with excitation maxima at 250/270 nm and emission maxima at 620/640 nm for gold and silver/gold nanoparticles, respectively. The labelled PLGA nanoparticles (140 nm) were characterised by dynamic light scattering (DLS), scanning electron microscopy (SEM), and UV–Vis and fluorescence spectroscopy. Their uptake by HeLa cells was followed by confocal laser scanning microscopy. The metallic nanoparticles remained inside the PLGA particle after cellular uptake, demonstrating the efficient encapsulation and the applicability to label the polymer nanoparticle. In terms of fluorescence, the metallic nanoparticles were comparable to fluorescein isothiocyanate (FITC).

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